Fireflies. Where are the options for clamping in 2.8?
You have to be in cycles.
Then you will have the option in the Light paths section.



Most fireflies can be dealt with by clamping indirect light.

Be careful not to use very small values, as they will make the scene much darker.

Reaed: Cycles: Emission Shader does not bring enough light

Read also: What is Clamp Direct/Indirect?

and:

How to reduce fireflies in Cycles?

What is the Reason Cycles Creates Incorrectly Colored/Firefly Artifact Pixels?

Managing/Reducing noise in a night scene